A tariff refers to

A tariff is a tax imposed on imported goods by the government of the importing country. The purpose of a tariff is to make the imported goods more expensive and less competitive compared to similar domestic goods. The goal of a tariff is to protect domestic industries from foreign competition, increase revenue for the government, and promote the consumption of domestic goods. Tariffs can be specific, meaning they are a fixed amount per unit of goods, or ad valorem, meaning they are a percentage of the value of the goods being imported.